Most conventional detergent compositions contain mixtures of various detersive surfactant components. Commonly encountered surfactant components include various anionic surfactants, especially the alkyl benzene sulfonates, alkyl sulfates, alkyl alkoxy sulfates and various nonionic surfactants, such as alkyl ethoxylates and alkylphenol ethoxylates. Surfactants have found use as detergent components capable of the removal of a wide variety of soils and stains. A consistent effort however is made by detergent manufacturers to improve detersive properties of detergent compositions by providing new and improved surfactants.
A problem commonly associated with surfactants is their apparent sensitivity to free ions in solution. It is believed that an increase in the number of free ions in solution generally results in reduced surfactant performance. The presence of hardness ions (calcium or magnesium ion), which occur naturally in the wash solution, in particular, can reduce surfactant performance. Anionic surfactants are especially sensitive to hardness ions, reducing surfactant performance, eventually precipitating the surfactant from solution as a calcium or magnesium salt.
It is the surprising finding of the present invention that in comparison to other more widely known anionic surfactant components, the dianionic or alkoxylated dianionic cleaning agents utilized herein provide improved cleaning performance in the presence of relatively high levels of hardness ions. Thus, when used in combination with other surfactants in a surfactant system, they provide liquid cleaning compositions having superior cleaning properties. They are especially effective when used in laundry cleaning processes.
In addition, the present invention liquid cleaning compositions are particularly useful for personal cleansing uses, as formulated for use as hair shampoos and body washes.
An advantage of the present invention is the improved cleaning performance of liquid detergent compositions formulated containing the described dianionic or alkoxylated dianionic surfactant component as a part of the total surfactant system.